This research was conducted in Pasir Putih, Situbondo district, East Java with the aim of mapping coral reef ecosystems and analyzing the condition of coral diversity to support learning Geography in remote sensing courses. Coral reef maps were extracted from Sentinel-2 satellite imagery by applying a water column correction algorithm. Mapping of coral reef areas resulted in 3 categories, namely live coral with an area of 32,860 Ha, dead coral 31,690 Ha, and sand 42,670 Ha with a level of 72.2 percent which is included in the good category. Testing the accuracy of the extracted map using the confusion matrix method based on 90 field survey data. The accuracy of the resulting map met the accuracy standard specified in SNI No. 7716:2011 for M...